contestada

A narrow copper wire of length L and radius b is attached to a wide copper wire of length L and radius 2b, forming one long wire of length 2L. This long wire is attached to a battery, and a current is flowing through it. If the electric field in the narrow wire is E, the electric firld in the wide wire is.a. Eb. E/4 c. 4E d. E/2 e. 2E

Respuesta :

Manetho

Answer:

E.

Explanation:

As we know that Current in both wire  will be same but both have different resistance as per

[tex]R_1 = \rho L/A[/tex]

[tex]R_2 =\rho L/4A[/tex] (As the radius is doubled so cross sectional area will become four times).

Hence,  [tex]R_1 = 4\times(R_2)[/tex]

therefore,  if current is same in both then voltage will be -

[tex]V_1=4\times(V_2)[/tex] (As V proportional to R , i is same in all)

then-

[tex]E_1 = 4(E_2)[/tex] (As E proportional V , r is same in all)

[tex]\Rightarrow E2 = \frac{(E_1)}{4}[/tex](Electric feild in wide wire)

Option E.

Otras preguntas